Images by Genevieve Carbonatto With M mode , the transition point can be recorded . On the M mode trace, on the right, note the statosphere sign associated with a pneumothorax (absence of lung sliding) and on the left the seashore sign seen with lung sliding
Right lung: Lung sliding – no pneumothorax
Left lung: absent lung sliding – pneumothorax
Transition point: Point at which the normal lung and pneumothorax meet. It moves with respiration